Improvement in grinding-plates fob grist-mills



SHAW & LEAVITT'.

Grinding Plate for Mills.

" Patented July 14, 186.8.

NEW DR gnitrh gnites again f g Letters Patent No. 79,8fi5 'dated m 14, 1868.

IMPROVEMENT IN GRINDING-PLATES FOR GRlST-MILLS.

dilge' Stimuli t'titttth in ii flgisz new new urinating mil Mike time.

:lO ALL WHOM IT MAY CONCERN: v

Be it known'that we, HENRY SHAW and WILLIAMD. LEAVITT, of the city of New -Orleans,.parish of Orleans,rand State of Louisiana, have invented a'certain neiv and use'ful Improvement in Cast-Iron Grinding Plates for Grist-Mills; and we do hereby declare the following to be a. full, clcar, and exact description of the same, reference being-had to the -annexed drawing," making a part of thisspecification; on which isdelinqated a perspective view of one of the grinding-plates of a cast-iron grist-milh with a part. broken away in order the more clearly to exhibit the most important'features of Oilr'lDVGIliZlOII. I t Our invention has for its object the prevention of the injurious and often destructive effects caused toth meal by the heat gcnerated in all mills through the friction of 'the.ru bbi igsuifaces 0f the two dpposing plates during the operation of grinding; and we attain this object by constructing each of the two g'rinding-plates in tvvo parts,'viz, a grinding-face plate, and a back or snpporting-plate,ivith an intermediate part or packing of unyielding and non-conducting properties, so that the two grinding-faces will consist of thin plates, and sothat such heat as is generated by'the friction caused-in grinding, beingv prevented from communicating to the remaining part of the plate, or any other part of the milh'or, inother'words, heing confined to the thin grindingfaee, will pass elf-with the meal as fast as the latter is ground, and before'o suflieient quantity of heat is gone rated or accumulated to injure the meal. I I V Another feature of our invention, having in view the furtherance, of the same object, is the peculiar dress" oftho grinding-faces of our plates, which consists of a system of diamond-shaped projections, \vhich radiatesin rows or l'incs from the centre of the face-plate, .and are so arranged that in the revolution of the running plate against the stationary one, a multitude of cutting-edges is created, which come together after the manner of the blades of a pair of shears, and-so cutthe grain, instead of crushing or breaking it, as is the case. in'most mills. It will readily'be seen that this shearing or cutting process reduces, to a-certain extent, the tendency to overheating, by reducing the friction of the plate against the grain.

' But our invention-will be better understood by referring to thedrawing, on which A'ropresents the d,iamond-' shaped drcss,'upon'the thin g'rinding-faceQB, of 'thc'platc. G is the non-conducting, unyielding intermediate packing which may he composed-of gasket, paper, or any other substance havinglunyielding andnon eondncting properties. D is the back part or supporting section of 'the' g rinding-plate,to-which the face-plate B is secured by strong screw-bolts (shown at E in the drawing) passing throughand confinin g in its position the intermediate a cking C, the whole forming, when screwed u a, t ong and compact grinding-plate.

Thedrawing. shows only onc of the grinding-plates, but it will be understood that in each mill there is another plate precisely similarto the one shown in, thedrawing as to its dres s" and sectional or divisional construction. I I g i I Having thus described our invention, we claimfand desire to secure by Iietters'Patent- 1 v The combination andarrengement o iltho' cast-iron. grinding plate 3, having diamondshaped projections A,

the unyielding, non-conducting paper packing O, and back plate D,- all constructed and secured together in the manner and for the purpose herein described.

- .c HENRY SHAW;

W. ;D; LEAV ITT Witnesses H. S. Brioon,

H. N. Jiamrms. 

